It’s a process that lightens discolorations and removes stains from the enamel and dentin of the teeth.
There are many causes, and there is a distinction between internal and external stains.
- internal stains: aging, trauma, tetracycline (while teeth are forming), excessive fluoride (greater than 10 ppm while teeth are forming), nerve degeneration
- external stains: coffee, tea, tobacco, some juices (grape, apple) – over years these can also get into the enamel crystals and become internal stains
- home, professional << RECOMMENDED
Professional home bleaching is very effective and has long lasting results. It most often utilizes custom mouth trays and viscous bleaching gels. Typically the gel is a carbamide peroxide (10-35%), but can be a hydrogen peroxide (7.5-9.5%). We use carbamide peroxide since it has less sensitivity.
In-office professional whitening typically uses bleaching gels that are light activated, e.g. Zoom, BrightSmile.
Several studies have shown that the benefit of the light, if any, is pretty much negligible. These studies utilized a split-arch evaluation of a whitening system utilizing a light on one half of the arch and no light on the other half. The conclusion reached is that the results were the same regardless of whether a light was used or not. - Mennito, Anthony S., D.M.D, A Simple Guide to Tooth Whitening, Aug. 2006
Whitening strips are effective, although they whiten teeth slowly, AND require reapplication at least every 6 months. Professional whitening is far more effective for darker colored teeth, easier to use, and faster. Whitening toothpastes and related over-the-counter products are for external stains.
Who May Benefit From Teeth Whitening?
Almost everyone. However there are some cases where the treatment may be less effective. The most difficult situations to whiten are those teeth with tetracycline staining. Also, and this is important, teeth whiten; however, crowns (caps), fillings, and veneers do not. If you are planning any crowns, fillings and/or veneers as part of your overall treatment, you may want to whiten your teeth first.
During The Process
Sometimes the biting edges and the sides of the teeth whiten more quickly than the rest of the teeth. This occurs because your enamel is thicker in these areas and responds faster to the whitening process. As you continue to use the whitening gel, the rest of your teeth will catch up and the color will even out.
Is The Process Safe?
Yes, extensive research and clinical studies indicate that whitening teeth under the supervision of a dentist is safe. In fact, many dentists consider whitening the safest cosmetic dental procedure available. Tooth whitening product is not recommended for children under 13 years of age and women who are pregnant or breast-feeding (in office whitening is not recommended for children under 18 years of age).
The whitening process does not damage enamel or weaken a tooth. For some people, teeth become more sensitive during the process, but this always goes away when you stop the whitening process (if you’re doing the home professional whitening and teeth become sensitive consider using your trays every 2nd or 3rd day rather than discontinue). The bleaching gel can be quite irritating if it gets on the gums.
Evaluation (before whitening)
- no cavities (examination and x-rays required)
- all fillings, crowns, etc. sealed tightly
- not recommended during pregnancy or nursing
- 13 years or older
- fillings, veneers, crowns, bonding (i.e. restorative materials) will not whiten
- teeth may become more sensitive during whitening – reversible when stopped
Products And Methods
I recommend home professional whitening with trays as the most effective. The home professional whitening I prefer utilizes concentrated carbamide peroxide whitening gel in custom mouth trays (custom whitening trays are critical to making the process effective). 30-minute* treatments for 10-14 days typically begin the process; however, the final result is something you determine.
Store whitening gel out of sunlight and away from heat.
* 30-35% carbamide peroxide gels are the most concentrated gel available for home use. At this concentration the maximum wear time is 30 minutes. If desired, two 30-minute sessions can be used with a minimum 4 hour interval between sessions (no more than 2 sessions per day).
Home professional whitening requires two short office visits:
- evaluation: find out what you want to accomplish and evaluate your teeth (color, shape, etc.), make the molds of your teeth for the custom whitening tray
- try-in and deliver the custom whitening tray, answer your questions, and review instructions
NOTE: Some professional home bleaching products still have directions for night time or extended (2 or more hours) wear, but current research shows that effective whitening does not occur after the first hour. What will occur with longer wear is an increase in sensitivity.